Automatic clutch mechanism



FCB 26, 1946- l. F. MooNEY 2,395,576

ATOMATIC CLUTCH MECHANISM Original Filed March 5, 1941 I y I /A/ l/E/V TOR lAweeA/cg EANC/s MoRoA/EV ATTO RA/Ey Patented Feb. 26, 1946 AUTOMATIC CLUTCH MECISM Laurence Francis Moroney, Moonee Ponds, near Melbourne, Victoria, Australia Original application March` 5, 1941, Serial No. 381,865. Divided and this application March 3, 1942, Serial No. 433,171. In Australia May 1,

11 Claims.

This invention relates to improvements in- `ferential teeth on its inner surface and means adapting it for fixture to a driven member coaxially aligned with the driving shaft, a pawlcarrying member (hereinafter termed rotor) rotatable about the driving shaft within a chamber formed in the casing, a spring-pressed pawl or pawls pivoted on the rotor and adaptedto be forced into locking engagement with the casing teeth, and an operating member xed on the driving shaft. In the form of the invention designed as a bi-directional clutch, two spring-pressed lpawls are pivoted on the rotor and the operating member on the driving shaft is so constructed that upon rotation of said shaft in eithervdirection the said operating member actuates both pawls simultaneously and causes them to lock the rotor relatively to the casing, whereby the driving shaft, the rotor, the casing, and the driven member are rotated unisonally. The said driven member may be secured to the casing, or it may be formed integrally therewith. Upon discontinuance of the rotative force applied to the driving shaft, the pawls are immediately withdrawn from their locking engagement with the casing teeth by the force of the springs acting upon them.

Reference is now made to the accompanying explanatory drawing, wherein:

Figure 1 is a view in frontV elevation of. the clutch mechanism assembled for aflixture to the driven member of a mechanism.

Figure 2 is a View in rear elevation of the same.

Figure 3 is a side elevation illustrating the clutch mechanism secured to the driven member which consists of a sprocket wheel.

Figure 4 is a sectional view on the line 4-4 of Figure 3, showing the integers of the clutch mechanism disengaged.

Figure 5 is a sectional view similar to Figure 4, but illustrates the pawls forced outwardly by the operating member on the driving sh'aft whereby their teeth are in engagement with the casing teeth.

Figure 6 is a sectional view of the clutch mechanism taken on the line 6 6 of Figure 1.

Figure 7 is a front elevation of the rotor.

Figure 8 is a sectional elevation illustrating a modied construction of the mechanism according to which the driven member is formed integrally with the casing of the clutch and wherein the arrangement of the pawls is such as to provide a uni-directional clutch in lieu of the bidirectional clutch illustrated in Figures 1 to 7.

Figure 9 is a sectional View taken of the line 9-'-9 of Figure 8.

Figure l0 is a transverse section of the combined clutch casing and driven member shown in Figures 8 to 9.

Reference is made initially to Figures 1 to 7 wherein 2 is a sprocket wheel, indicative generally of a driven element which is to be ro-tated by operation of the clutch mechanism. A casing 3 is secured to the sprocket wheel by bolts passed through holes 4 formed in an attachment ange 5 With which the casing is provided. The casing comprisesV a cylindrical member 6 having at one end a central tubular boss 'I. The casing is formed interiorly with equidistant circumferential teeth 8 and having a cylindrical chamber 9 having a smooth internal surface and of larger diameter than the pitch circle of said teeth. y

I0 indicates a driving shaft passed through' vthe tubular boss l' and having one end projecting outwardly beyondsaid boss whereby it is adapted to be engaged or rotated by a driving mechanism which may be of any suitable type. The inner v end of the driving shaft is provided with an operating member I I which' may be formed integrally with said shaft or xedly secured thereto. This operating member consists of a short lever arm I 2 having on opposite sides thereofv cam members I3 and- I 4 which are for the purposes to be hereinafter explained.

Ftting within th'e chamber 9 of the casing 3 is a rotor I5 whichis formed with diametrically opposite stop members I 6 and I1 and opposed jstuds I8 and I9. The rotor is dimensioned to t freely between the' internal teeth 8 of the casing 3 with the stops I6 and I'I and the studs I8 and I9 on said rotor projecting within the chamber 9. A shallow recess 20 is formed centrally on the inner surface of the rotor and serves as a support and bearing for the inner/end of the shaft I Il. The stops I6 and I'I are designed to clear the teeth 3 during rotation of the rotor I5 relative to the casing 3, and the studs I8 and IS are set inwardly a short distance from the perimeter of the rotor so that pawls 2I and 22 which are pivotally mounted on said studs will clear the teeth 8 by a short distance. Y

The pawls 2I and 22 are of curved configuration and formed with flat radial surfaces 23 and 24 at their opposite ends, and they are apertured at approximately mid-position to pivotally fit on the studs I 8 and I9. Thus pivotal movements imparted to the pawls are restricted by the stops I6 and I'I, the flat surface 23' bearing evenly upon one side of the stop I6 at one limit of a movement and the surface 2li bearing similarly upon a side of the opposite stop Il atthe other limit of the movement.

Fitted within a hole 25 in the stop I6 is a short helical compression spring 26 having its opposite ends projecting beyond the sides of the stop. The ends of the spring press upon the flat surfaces 23 of the pawls 2I and 22 forcing the same apart to the limit of permissible movement determined by the opposed flat surfaces 24 abutting against the sides of the stop I'I. Each of said pawls has'one or more teeth 2'I formed on its outer curved surface near the flatradial surface 24, and its inner surface is shaped to the configuration of a cam 28.v The proles of the pawls preferably are identical in order that an 4interchange of the pawls may be effected without affeotingthe operation of the mechanism.

The operating member II xedon the inner' `end of the driving shaft I fits between the pawls 2I-22 with its lever arm I2 disposed between the at surfacesll of said pawls and its cam members I3 and I in Contact with the cam surfaces 28 provided on the inner sides of said pawls. The

Y. spring 26 is of such strength that it will absorb slightruncontrolled forces exerted by the operatfing member IIso as tothereby prevent the pivoted pawls being actuated by slight vibrator-y movements of the driving shaft Il).

n jWhen the shaft I is driven in either direction.

" bythe` mechanism connected to its outer end, initial rotation of the operating member causes the spring 26 toyield before the closely fitted rotor lcan overcome its frictional drag-to start to rotate, .and thus the member II causes the pawls' 2I `and 22 to turn on their pivot studs I8 and I3, respectively, against the pressure exerted .by the v'spring 2S so that the pawl'teeth 21 are forced outwardly into engagement with the internal circumferential teeth 8 of the casing 3. The pawlvs 4are locked in engagement with the casing teeth as long asthe rotational force exerted byV the driving shaft I continues. Consequently the rotor I carrying the pawls is locked relatively to the casing 3 and an operative connection between the driving shaft and said casing is effected Vand furtherrotatable movement of the driving shaft 'will' cause said casing with the driven member fastened thereto to be rotated. I Y Upon release ofthe driving force applied by "the shaft IG the compressed spring 26 will impart pivotal movement to the .pawls 2I and 22 whereby their teeth 2'I will be withdrawn from engagement with the teeth 8 of the casing 3 whereupon `said casing with the driven member 2 that is secured thereto may continue to rotate yfreely or it may cease to rotate, depending upon the nature of .the said member 2. j y Y'I'heipawl operating member I'I is symmetrical `'in' 'conguration and the pawls 2i and 22 are Y In Figures 8 to 10 I have illustrated a modification of the improved clutch mechanism according to which the casing 3 and the driven member 2, instead of being formed separately and then secured together as hereinbefore described, are formed integrally. As an example of this unitary construction, the casing 3 is illustrated as one formed with external circumferential teeth 28 and having internal circumferential teeth 8 and a chamber 9 having a smooth internal surface as previously described. The rotor I5 is freely rotatable within the chamber 9. The driving shaft I6 is passed through a hole 29. formed axially in said rotor and it extends through the j casing 3. The operating member II fixed on the shaft I fits between the pivoted -pawls 2i. A

cover plate 3i) formed with a boss 3i to thus provide a bearing for said shaft is bolted tothe casing 3 whereby the integers of the mechanism aremaintained in correct operative relationship.

The bi-directional clutch mechanism hereinbefore described may be modified to provide a uni-directional clutch. This is accomplished by omitting one of the pivoted pawls 2l and Substituting for the pawl-operating member I I a simple .lever arm fixed onY the driving shaft I0 to operate similarly to the lever arm I2 of said member I'I. Alternatively, there may be formed on the face of the rotor i5 two 'opposed stops I eachhaving a socket 32 accommodating a helical compression spring 2S'. These springs act upon the flat surfaces 23 of two pawls 2I pivoted on studs IB integral with the rotor I5. A double-acting lever 33, which is non-turnably fixed on the driving shaft Ill, acts upon the ends of the'pawls 2I so that rotation of the driving shaft in clockwise direction causes the pawl teeth 2I to engage the teeth Y3 of the casing 3 and -be maintained in mesh until discontinuance of the driving force exerted on the shaft, whereupon the springs 26 acting upon the Opposite end portions 23 of the pivoted pawls `causes their teeth 21 to be withdrawn from locking engagement with 'the casing teeth.

WhatIdoclaimis: f Y y 1. Clutch mechanism vcomprising a cylindrical casing formed with teeth arranged circumferentially around its innerv surface and adapted for fixture to a driven memberico-axially aligned with a driving shaft, Ya circularchamber formed in, said casing, a rotor within said chamberrotatable about the driving shaft, a pivoted'pawl on said rotor having one end adapted 'for engagement with said casing teeth, said. pawl having an arcuate shapeand being pivoted medianly, and the other end being non-engageable, 'aspring acting on one end 'of said pawl .tending to keep the other end -free from said casing teeth, and operating means on the driving shaft arranged upon vrotation of said shaft to engage said vother end of said pawl andato pivotally actuate. said pawl against the pressure of said spring and force it into locking engagementwith the casing teeth.

2. Clutch mechanism, according to `claim 1, and wherein the casing is formedY integrallywith .the driven member;

3. Clutchmechanism according to claim 1, and

wherein the casing is formed circumferentially with external teeth for the purposes described.

4. Clutch mechanism according to claim 1, and wherein the chamber for the rotor is formed peripherally on the casing and is of larger diameter than the pitch circle of the teeth formed on the inner surface of said casing and a recess is formed centrally in the rotor to support the inner end of the driving shaft.

5. Clutch mechanism according to claim 1, and wherein the pivoted pawl is formed having at one end a fiat radial surface upon` Which the spring presses and teeth at its opposite end adapted for locking engagement with the casing teeth.

6. Clutch mechanism according to claim 1, and wherein the pivoted pawl has flat radial surfaces at its opposite ends, a stop limiting the pivotal movement of said pawl is formed on the rotor, a compression spring is fitted in a hole in said stop and presses upon one of the flat surfaces of the pawl. and teeth are formed at the opposite end portion of the pawl adapted for engagement with the casing teeth.

'7. Clutch mechanism according to claim 1, and wherein the pivoted pawl has fiat radial surfaces at its opposite ends, a stop limiting the pivotal movement of said pawl is formed on the rotor, a compressing spring is fitted in a hole in said stop and presses upon one of the flat surfaces of the pawl, teeth are formed at the opposite end portion of the pawl, and a lever is fixed on the driving shaft and is adapted upon rotation of said driving shaft in clockwise direction to impinge against a fiat surface of the pawl and impart pivotal movement thereto whereby its teeth are forced against the pressure of the spring into locking engagement with the casing teeth.

8. Clutch mechanism comprising a cylindrical casing formed with teeth arranged circumferentially around its inner surface and adapted for fixture to a driven member co-axially aligned with a driving shafty a circular chamber formed in said casing, a roto-r within said chamber rotatable about the driving shaft, studs on said rotor, a pair of spring-pressed pawls of arcuate shape pivoted medianly on said studs and having teeth on diametrically opposite ends designed for locking engagement with the casing teeth and the other ends being non-engageable, and a doubleacting lever fixed on the driving shaft adapted to simultaneously actuate said pivoted pawls upon the rotation of the driving shaft in one direction and thereby lock said rotor relatively to said casing, whereby said driving shaft, rotor, casing and driven member are rotated unisonally in one direction and upon rotation of the driving shaft in the opposite direction said pawls are inoperative.

9. Clutch mechanism comprising a cylindrical casing formed with teeth arranged circumferentially around its inner surface and adapted for fixture to a driven member co-axially aligned with a driving shaft, a circular chamber formed on said casing, a rotor disposed Within said chamber rotatable about the driving shaft, a pair of oppositely arranged spring-pressed pawls pivoted on said rotor and having teeth designed for engagement with the casing teeth, said pawls being arcuate shaped and pivoted medianly, and an operating member fixed on the driving shaft and operative to engage adjacent ends of the pivoted pawls, said operating member being adapted to simultaneously actuate the pawls upon rotation of the driving shaft in either direction so that the pawl teeth are forced into engagement with the casing teeth to lock the rotor to the casing whereby the driving shaft, rotor, casing and driven members are rotated unisonally.

10. Clutch mechanism according to claim 9, and wherein the rotor has diametrically opposite stop members and the pawls pivoted on said rotor have inner surfaces of cam shape with iiat radial surfaces at their opposite ends, and wherein the operating member fixed on the driving shaft consists of a lever arm positioned between opposed fiat surfaces of said pawls and cam members to co-act with the cam-shaped surfaces of said pawls. f

ll. Clutch mechanism according to claim 9, and wherein the rotor has diametrically opposite stop members and the pawls are pivoted at approximately their mid positions on studs carried by the rotor, said pawls having inner surfaces of cam shape with fiat radial portions at their opposite ends, a compression spring tted in a hole formed in one of said stop members presses upon opposed fiat portions of said pawls, and wherein the operating member fixed on the driving shaft consists of a lever arm arranged between opposed at portions of said pawls at the ends thereof opposite to those whereo-n said spring presses and cam members adapted to co-act with the cam-shaped surfaces of said pawls, the said lever arm and cam members being of integral construction.

LAURENCE FRANCIS MORONEY. 

